The present invention relates to a method for administrating viable microorganism compositions to poultry in which viable microorganism compositions useful for the growth of poultry are administered, thereby feeding the poultry with a high productivity while reducing the amounts of medicaments, such as antibiotics, antibacterial agents and the like, or without the administration of the medicaments.
In the feeding of poultry, such as broilers and the like, dense rearing of 40 to 60 birds per 1 tsubo (ca. 3.3 m2) of a poultry farm is generally carried out in order to reduce the production cost. Furthermore, poultry is fed in to achieve rapid growth, 40 to 55 g in average daily body weight gain, so that the birds may be shipped by about 2 months after hatching. Under these conditions, the poultry is always under great stress, and they often become sick, and diseases often spread among the poultry. In floor feeding, since the poultry pecks the feed and the like, which are smeared with excrement on the floor, toxic bacteria spread very easily upon all the birds in the feeding facility. Also, in an open feeding facility, or even in a windowless feeding facility in some cases, toxic bacteria can easily spread across the feeding facility. In addition, for example, although a broiler house is disinfected every time when broilers are shipped, since small animals, such as rats and the like, in the surrounding area are not affected by this treatment, and these animals carry bacteria, such as salmonella and the like, into the poultry house when broiler chicks are again put into the feeding facility.
In order to maintain high productivity while preventing a decrease in the rate of growth and the like during the feeding period, and also to prevent the contamination of the poultry with toxic bacteria under these conditions, various medicaments, such as antibiotics, antibacterial agents and the like, are generally administered to the poultry.
However, since these exists the possibility of residual medicaments in the meat and eggs, and also the danger of generating bacterial strains resistant to the medicaments (as has actually been reported in many cases), demand has been increasing among users for drug-free livestock farm products, produced without using medicaments.
On the other hand, under natural conditions without dense rearing of a large number of poultry, high productivity cannot be expected. However, it is possible to raise poultry, such as chickens and the like, without using medicaments, such as antibiotics, antibacterial agents and the like. The meat and eggs of chicken raised under natural conditions, namely so-called yard native chicken, are now in great demand because of the safety and good taste, and traded on the market at a high price.
Consequently, great interest has been directed toward the development of a feeding method for raising poultry, such as chickens and the like, without causing contamination with toxic bacteria, while maintaining high productivity, by a drug-free feeding method (feeding in which medicaments, such as antibiotics, antibacterial agents and the like, are not used during part of, or through the entire, period of feeding, so that the medicaments do not remain in the birds, at least at the time of shipping).
When the conventional dense rearing of large numbers of poultry is carried out by merely avoiding the administration of medicaments, the poultry are easily infected with toxic bacteria. Therefore it is not possible to maintain productivity at a commercially acceptable level without causing contamination with toxic bacteria.
As a means for reducing the infection of poultry with toxic bacteria without depending on medicaments, such as antibiotics, antibacterial agents and the like, it has been proposed to administer microorganisms and the like which are useful for the growth of various poultry. Bacteria belonging to the genus Bacillus, lactic acid bacteria belonging to the genus Lactobacillus, bacteria belonging to the genus Bifidobacterium and the like are known as useful microorganisms for feed additive or as various CE (competitive exclusion) preparations. Some of these microorganisms are commercially available as feed additive viable microorganism preparations for poultry. However, although the effects are recognized to some extent, they are not sufficient. Particularly, no means has been reported which can carry out drug-free feeding of poultry in dense rearing, with a large number of poultry, and with productivity at a commercially acceptable level by providing these viable microorganism preparations.
For example, Japanese Registered Patent No. 2528055 and JP-B-3-79988 (the term xe2x80x9cJP-Bxe2x80x9d as used herein means an xe2x80x9cexamined Japanese patent applicationxe2x80x9d) disclose that body weight gain and feed conversion ratios in animals can be improved and effects, such as intestinal function controlling action and the like, can be obtained by administering a viable microorganism preparation comprising Bacillus subtilis to animals. It is possible to carry out drug-free feeding by applying the means to, for example, broilers, but only in a certain limited regions where broilers are not produced on a large scale. However, in many regions where broiler feeding is frequently carried out, since they are often infected with toxic bacteria which spread easily through the feeding facilities as described above, it is extremely difficult to carry out commercial drug-free feeding of broilers using this means. Also, even if drug-free feeding of broilers using this means were possible, the body weight gain rate of the poultry is slower than feeding using medicaments. As a result, the high productivity of the drug-applied feeding is not obtained.
In addition, the viable microorganism preparations currently on the market have problems, such as the reduction of the viable count during the distribution steps, the poor colonization ability after the formation of intestinal bacterial flora, the necessity for the continued administration of the viable microorganism preparations for a prolonged period of time, and the like. Particularly, the necessity for the continued administration of the viable microorganism preparations for a prolonged period of time, due to the poor colonization ability after the formation of intestinal bacterial flora, is presently a serious obstacle to the practical use from the viewpoints of economics.
An object of the present invention is to provide a method for administrating viable microorganism compositions to poultry, so that drug-free feeding of poultry can be carried while maintaining good productivity.
For resolving the above-mentioned problems, the inventors of the present invention have carried out screening of useful bacteria from broad natural sources, and have found that certain lactic acid bacteria isolated from the intestinal tract of a chicken can be easily colonized in the intestinal tract of newborn chickens shortly after hatching. Also, the inventors have found that particularly a heterofermentation lactic acid bacterium isolated from the ileum of a chicken and a homofermentation lactic acid bacterium isolated from the cecum of a chicken can easily be colonized on the intestinal tract of newborn fledglings and have various effects, such as inhibition of the growth of toxic bacteria, prevention of diarrhea, enhancement of growth, improvement of the rate of raising, improvement of the feed conversion ratios and the like. In addition, the inventors have found that lactic acid bacteria can be colonized on the intestinal tract of newborn chicks soon after their birth by merely spraying a suspension of viable microorganisms of these lactic acid bacteria of the genus Lactobacillus only once to newborn chicks within 4 days after hatching.
Furthermore, the inventors have found that, when useful lactic acid bacteria are colonized in combination with the administration of Bacillus subtilis viable microorganisms during a period from the fledgling stage to the mature bird state in the drug-free feeding of poultry, body weight gain at the initial feeding stage can be improved and a sufficient rate of raising can be obtained in comparison with the single administration of Bacillus subtilis viable microorganisms, so that it becomes possible to carry out drug-free feeding of poultry by dense rearing in a large number of poultry with commercially effective high productivity. The present invention has been accomplished on the basis of these findings.
Thus, the present invention relates to a method for administering viable microorganisms to poultry, comprising:
administering a first composition to a poultry comprising viable bacteria belonging to Lactobacillus reuteri and Lactobacillus johnsonii, at the stage of newborn fledgling.
Furthermore, the present invention relates to a method for administering viable microorganism compositions for poultry, comprising:
administering a viable microorganism composition for poultry comprising viable lactic acid bacteria belonging to Lactobacillus reuteri and Lactobacillus johnsonii at the stage of newborn fledgling; and
administering a viable microorganism composition for poultry comprising a viable microorganism belonging to Bacillus subtilis. 
The method of the present invention for administrating viable microorganism compositions for poultry, includes a viable microorganism composition for poultry comprising viable lactic acid bacteria belonging to Lactobacillus reuteri and Lactobacillus johnsonii (hereinafter often referred to as a xe2x80x9cviable microorganism composition of lactic acid bacteriaxe2x80x9d) is administered to newborn fledglings.
The above-described lactic acid bacteria belonging to the genus Lactobacillus are facultative anaerobic bacteria. Not only those isolated from the intestinal tract of poultry but also other strains isolated from a natural source can be used effectively. Preferred examples of the strain belonging to Lactobacillus reuteri include Lactobacillus reuteri CP-720 (Deposit No. FERM BP-6332), Lactobacillus reuteri CP-722 (Deposit No. FERM BP-6334) and the like. Preferred example of the strain belonging to Lactobacillus johnsonii includes Lactobacillus johnsonii CP-721 (Deposit No. FERM BP-6333) and the like. These three strains have been deposited at National Institute of Bioscience and Human-Technology, Agency of Industrial Science and Technology (Address: 1-3, Higashi 1 chome, Tsukuba-shi, Ibaraki-ken 305-8566, Japan) on Apr. 27, 1998. Other strains of Lactobacillus reuteri and Lactobacillus johnsonii are known, such as those described in ATCC Bacteria and Bacteriophages, 19th ed., 1996, pages 195 and 197, hereby incorporated by reference.
Bacteriological properties of Lactobacillus reuteri CP-720 and CP-722 and Lactobacillus johnsonii CP-721 are shown in Table 1.
The viable microorganism composition of lactic acid bacteria may further contain heterofermentation lactic acid bacteria belonging to the genus Lactobacillus other than Lactobacillus reuteri, such as Lactobacillus brevis, Lactobacillus buchneri and the like, and also homofermentation lactic acid bacteria belonging to the genus Lactobacillus other than Lactobacillus johnsonii, such as Lactobacillus gasseri, Lactobacillus crispatus and the like, belonging to the Lactobacillus acidophillus group. Many different strains of many different genera of Lactobacillus are known, such as those described in ATCC Bacteria and Bacteriphages, 19th ed., 1996, pages 192-199, hereby incorporated by reference.
Preferred examples of the medium which can be used in culturing the viable microorganisms of lactic acid bacteria include a milk medium, such as cow""s milk, goat""s milk, horse""s milk and the like, skim milk thereof and a medium for lactic acid bacteria, such as BL medium, Briggs liver broth medium, MRS medium, GAM medium, TTY medium and the like.
The lactic acid bacteria can be cultured at 25 to 45xc2x0 C., more preferably 30 to 40xc2x0 C., and for 6 to 30 hours, more preferably 10 to 24 hours. The culture broth thus obtained can be used directly as the viable microorganism composition of lactic acid bacteria by storing as such at about 5xc2x0 C. until use. Alternatively, the microorganisms may be recovered by centrifugation, mixed with a protective agent and then freeze-dried in vacuo. The resulting powder of the bacteria can be stored in a cool and dark chamber and used as a viable microorganism composition of lactic acid bacteria by suspending, mixing or dissolving the powder when used. The powder of dry microorganisms prepared in this manner is more preferred because it can withstand long periods of storage.
The viable microorganism composition of lactic acid bacteria may contain a carrier and diluent. The carrier and diluent are not particularly limited, and selected from pharmaceutically or nutritionally acceptable carriers and diluents. Also, the viable microorganism composition of lactic acid bacteria may be contain a poultry feed (ration).
In the present invention, the microorganisms belonging to Lactobacillus reuteri and Lactobacillus johnsonii may be subjected to an appropriate mutation treatment, such as exposure to ultraviolet light, X-ray or radiation, and a chemical treatment with a mutagenic compound (e.g., nitrsoguanidine, acridine dye). Mutants may also be prepared by insertion, deletion or substitution of nucleotides, as well as spontaneous mutation. The terms Lactobacillus reuteri and Lactobacillus johnsonii include these mutants.
The term xe2x80x9cstage of newborn fledglingxe2x80x9d means just after hatching of the fledgling (e.g., chick, poult, squab or the like), specifically a period of 0 to about 4 days after hatching. The time for the administration of the viable microorganism composition of lactic acid bacteria is not particularly limited so long as during the stage of newborn fledgling; however, it is preferred to administer the composition within 4 days after hatching, more preferably within 2 days after hatching, a period before colonization of intestinal bacterial flora in the intestinal tract of the fledgling. The number of times of the administration is not particularly limited; however, sufficient effects can generally be obtained by a single administration. The effects obtained become more stable and secure as the number of times of administration increases. However, administration three times or more is not economical, and the effects obtained thereby are almost the same as administration two times.
Although not particularly limited, administration of the viable microorganism composition of lactic acid bacteria can be carried out by oral administration. Specifically, the composition can be orally administered by adding it to drinking water or the like and allowing fledglings to ingest it freely, or by spraying it from a position above the fledglings using a spray or the like. The spray administration method is preferred because of the habit of fledglings to chirp while opening their beaks upwards so that the viable microorganism composition having a high concentration can be orally administered at the stage of newborn fledgling easily and securely.
In carrying out the administration, the total density of lactic acid bacteria in the viable microorganism composition of lactic acid bacteria is preferably from 106 to 1010 viable microorganisms per g, more preferably from 107 to 109 viable microorganisms per g. In addition, the viable microorganism composition of lactic acid bacteria is preferably administered in an amount of 1xc3x97103 to 1xc3x9710xe2x80x83viable microorganisms per fledgling, more preferably 1xc3x97104 to 1xc3x97106 viable microorganisms per fledgling.
In the method of the present invention, a viable microorganism composition for poultry comprising a viable microorganism belonging to Bacillus subtilis (hereinafter often referred to as a xe2x80x9cviable microorganism composition of Bacillus subtilisxe2x80x9d) is administered in addition to the above-described administration of the viable microorganism composition of lactic acid bacteria.
Preferred examples of the strain of Bacillus subtilis include Bacillus subtilis C-3102 (Deposit No. FERM BP-1096) which has been deposited in Institute of Bioscience and Human-Technology (old name: Fermentation Research Institute), Agency of Industrial Science and Technology (Address: 1-3, Higashi 1 chome, Tsukuba-shi (old address: Yatabe-machi, Tsukuba-gun), Ibaraki-ken 305-8566 (old zip code: 305), Japan) on Jun. 28, 1986, and the like. Bacteriological properties of Bacillus subtilis C-3102 are already described in Japanese Registered Patent No. 2528055, JP-B-3-79988 and U.S. Pat. No. Re. 34,837. Many different strains of Bacillus subtilis are known, such as those described in ATCC Bacteria and Bacteriophages, 19th ed., 1996, pages 57-63, hereby incorporated by reference.
In culturing of Bacillus subtilis C-3102, an aqueous or solid medium containing materials, such as carbon sources, nitrogen sources, inorganic substances and the like, which are generally used in culturing of microorganisms can be used as the culture medium. Examples of the carbon sources include those which can be assimilated, such as glucose, fructose, sucrose, starch, molasses and the like. Examples of the nitrogen sources include peptone, meat extract, casein hydrolysate, ammonium sulfate and the like. As occasion demands, phosphates, salts of magnesium, potassium, sodium, calcium, iron, manganese and the like, vitamins, amino acids, antifoaming agents, surfactants and the like can further be added as inorganic components. Culturing is preferably carried out aerobically. The starting pH of the medium is preferably 5 to 9, more preferably 6 to 8; the culture temperature is preferably 20 to 50xc2x0 C., more preferably 35 to 40xc2x0 C.; and the culturing period is preferably 12 hours to 7 days.
The culture mixture obtained in this manner can be used as the viable microorganism composition of Bacillus subtilis as such or as its concentrated product or as cells isolated therefrom, directly or after adding additives such as fillers and the like. The fillers are not particularly limited, and examples include calcium carbonate, defatted rice bran, corn grits, corn flour, wheat bran, skim milk powder and the like.
The viable microorganism composition of Bacillus subtilis may be contain a carrier or diluent. The carrier and diluent are not particularly limited, and selected from pharmaceutically or nutritionally acceptable carriers and diluents. Also, the viable microorganism composition of Bacillus subtilis may be contain a poultry feed.
In the present invention, the microorganism belonging to Bacillus subtilis may be subjected to an appropriate mutation treatment, such as exposure to ultraviolet light, X-ray or radiation, and a chemical treatment with a mutagenic compound (e.g., nitrsoguanidine, acridine dye). Mutants may also be prepared by insertion, deletion or substitution of nucleotides, as well as spontaneous mutation. The term Bacillus subtilis includes these mutants.
The time of the administration of the viable microorganism composition of Bacillus subtilis is not particularly limited; however, in order to obtain appropriate colonization of intestinal bacterial flora, it is preferred to administer the viable microorganism composition of Bacillus subtilis after the administration of the above-described viable microorganism composition of lactic acid bacteria. Also, in the case of a feeding method in which antibiotics, antibacterial agents and the like are not administered during a period between the newborn fledgling stage and the finishing stage, it is preferred to administer the viable microorganism composition of Bacillus subtilis during that period. In the case of broiler feeding, for example, it can be administered during an optional period between the newborn fledgling stage and the finishing stage; however, when a drug-free feeding is carried out only during the grower stage and finishing stage so that the medicaments do not remain in the body of the broiler at the time of broiler shipping, the viable microorganism composition of Bacillus subtilis can be administered during the grower stage and finishing stage.
Administration of the viable microorganism composition of Bacillus subtilis can be carried out by oral ingestion after adding it to feed, drinking water or the like.
For example, when the viable microorganism composition of Bacillus subtilis containing Bacillus subtilis C-3102 is mixed with feed in carrying out the administration, it is preferred that the feed has a microorganism density of 105 to 108 viable microorganisms per gram in the form of spores and/or vegetable cells.
The method of the present invention for administering the viable microorganism compositions for poultry can be applied not only to chickens to be fed under dense rearing in a large number of birds but also to chickens to be fed under other conditions and to other domestic birds such as ducks, geese, quails, wild ducks, ostriches and the like, as well as pet birds and the like.
When the viable microorganism compositions for poultry are administered in the above-described method, an intestinal bacterial flora in which useful bacteria for the growth of poultry predominate can be formed in the intestines, so that the poultry grows in good health. Various effects, such as growth inhibition of toxic bacteria, prevention of diarrhea, enhancement of growth, improvement of the feed conversion ratios and the like, can be obtained, and drug-free feeding of chickens becomes possible. Also, since useful bacteria dominate the intestinal bacterial flora, the poultry grow in good health, so that delicious meat, eggs and the like can be obtained in the case of edible poultry due to markedly improved qualities of the products. In addition, the meat, eggs and the like are safe, and are not contaminated with toxic food poisoning bacteria.